The Trinity tells us so much. It tells us:
Who God is (i.e., that God is love)
Who we are and what we are made for (i.e., we are created in God's image and likeness and made for love)
That we are never alone (i.e., God wants to "move in" to our soul)
If you want to hear my homily about how the Trinity does not imply a logical contradiction, click HERE.